The present invention discloses a backlight module and a light guide plate (LGP) fixture thereof, wherein the LGP fixture comprises a LGP, a heat dissipation base and a plurality of clamps. The heat dissipation base is planar and correspondingly disposed below the LGP. The heat dissipation base is installed with the clamps on sides of the LGP. Each of the clamps has a bottom portion, and a retaining plate and at least one upright plate are vertically formed from the bottom portion. The upright plate and the retaining plate are clamped on the heat dissipation base, and the clamps are used to position the LGP.